Least favorite:
Cruising down a two lane (in my direction) road, I get stuck at a light in the left lane, behind someone who was waiting to turn. Light turns red, they go, I pull up and stop. This is an 'anything goes' lane.
This "dad" (said sarcastically) figure pulls up next to me in a Maxi... uh.... "ma".
The road ahead merges into one lane about 500 feet up.
Light turns green. I casually pull out, and this guy wants a piece.
We put them down, and we're dead even.
The merge came up real fast, and there was traffic ahead. I let up, and this (expletive), can't let me get ahead (hey, I was at the light first!). He pushes his car to the last second, NAILS his brakes and gets the car squirrely as he cuts in between me, who slowed down casually, and the stopped car in front of us.
He was then toying with me after that, doing the 'hard, quick, brake jab' thing. Whatever. He was probably mad the big pig was dead even with his car.
Good experience:
Went to pass someone on the highway the other day. I glance back and see a ricer coming up from way behind doing like 85+ in a 65.
I pass anyway and get to the middle lane again. The kid caught up to me and had to slow down. I hear the car make this sickly "HAAAAWWWWWWW" as he gets on the gas to speed back up.
Nope. Not today.
I "drop the hammer" ala Tom Cruise, and keep the little Integra behind me for a good amount of time. I backed off before the limiter with the car even to my back bumper.

I was giggling like an idiot for a good five minutes.